Answer:
Length = 74 feet,
Width = 65 feet
Explanation:
If length = l, width = w;
l = 9 + w (Given)
2l + 2w = 278 (Definition of perimeter)
Substitute "9 + w" for l in the second equation;
2(9 + w) + 2w = 278 -> Distribute the "2"
18 + 2w + 2w = 278 -> Combine like terms
18 + 4w = 278 -> Subtract 18 on either side
4w = 260 -> Divide either side by 4
w = 260/4 = 65 feet
l = 9 + 64 = 74 feet